Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Injury. 2022 Feb;53(2):368-375. doi: 10.1016/j.injury.2021.11.046. Epub 2021 Nov 23.
During tourniquet application, blood flow is restricted to a limb to stop excessive limb hemorrhage in a trauma setting and to create a bloodless operating field in the surgical setting. During tourniquet-related ischemia, aerobic respiration stops, and ATP is depleted, and during subsequent reperfusion, there is an increase in reactive oxygen species (ROS) production and other endogenous substances, which leads to acute ischemia-reperfusion (IR) injuries, including tissue necrosis and skeletal muscle contractile dysfunction. Hyperbaric oxygen (HBO) therapy can increase the arterial oxygen tension in the tissues of patients with general hypoxia/anoxia, including carbon monoxide poisoning, circulatory arrest, and cerebral and myocardial ischemia. Here, we studied the protective effects of HBO pretreatment with 100% oxygen at 2.5 ATA against tourniquet/IR injury in mice. After one hour of HBO therapy with 100% oxygen at 2.5 ATA was administered to C57/BL6 mice, a rubber band was placed at the hip joint of the unilateral hindlimb to induce 3 h of ischemia and then released for 48 h of reperfusion. We analyzed gastrocnemius muscle morphology and contractile function and measured the levels of ATP and ROS accumulation in the muscles. HBO pretreatment did not improve tourniquet/IR-injured gastrocnemius muscle morphology and muscle contraction. Tourniquet/IR mice with HBO pretreatment showed no increase in ATP levels in IR tissues, but they did have a decreased amount of ROS accumulation in the muscles, compared to IR mice with no HBO pretreatment. These data suggest that one hour of HBO pretreatment with 100% oxygen at 2.5 ATA increases the antioxidant response to lower ROS accumulation but does not increase ATP levels in IR muscles and improve tourniquet/IR-injured muscle morphology and contractile function.
在止血带应用过程中，血流被限制在四肢，以阻止创伤环境中肢体过度出血，并在手术环境中创造无血手术场。在止血带相关缺血期间，有氧呼吸停止，ATP 耗竭，随后再灌注时，活性氧（ROS）产生增加和其他内源性物质增加，导致急性缺血再灌注（IR）损伤，包括组织坏死和骨骼肌收缩功能障碍。高压氧（HBO）治疗可以增加包括一氧化碳中毒、循环停止和脑和心肌缺血在内的一般缺氧/缺氧患者组织中的动脉氧张力。在这里，我们研究了在小鼠中用 2.5ATA 的 100%氧气进行 HBO 预处理对止血带/IR 损伤的保护作用。在 C57/BL6 小鼠中进行一小时的 2.5ATA 100%氧气 HBO 治疗后，在单侧后肢的髋关节处放置橡皮筋以诱导 3 小时缺血，然后释放 48 小时再灌注。我们分析了比目鱼肌的形态和收缩功能，并测量了肌肉中 ATP 和 ROS 积累的水平。HBO 预处理不能改善止血带/IR 损伤的比目鱼肌形态和肌肉收缩。与没有 HBO 预处理的 IR 小鼠相比，用 HBO 预处理的止血带/IR 小鼠的 IR 组织中 ATP 水平没有增加，但肌肉中 ROS 积累量减少。这些数据表明，用 2.5ATA 的 100%氧气进行一小时的 HBO 预处理可增加抗氧化反应以降低 ROS 积累，但不能增加 IR 肌肉中的 ATP 水平并改善止血带/IR 损伤的肌肉形态和收缩功能。
